triacontagon

From Ancient Greek τρῐᾱ́κοντᾰ (triā́konta) +‎ -gon.

triacontagon (plural triacontagons)

1. (geometry) A polygon with thirty sides.
   • 1947, H. S. M. Coxeter, Regular Polytopes, published 2012, unnumbered page:

     After projection onto the (x₁, x₂) plane, the A’s, B’s, C’s, and D’s form four concentric triacontagons, inscribed in circles of radii a, b, c, and d.

   • 1964 July, B. L. Chilton, On the Projection of the Regular Polytope {5, 3, 3} into a Regular Triacontagon, Canadian Mathematical Bulletin, Volume 7, Number 3, page 386,

     In the projection the 600 points can be classified in 12 sets: each set consists of either of 30 or of 60 vertices which lie on a circle concentric with the outer triacontagon.

   • 1997, Johannes Kepler, E. J. Aiton, Alistair Matheson Duncan, Judith Veronica Field (translators), The Harmony of the World, [1619, Harmonices Mundi], American Philosophical Society, Volume 309, page 59,

     What should the decision now be about the sides of the Triacontagon?

• (30-sided polygon): 30-gon

• triacontagonal